Spectral analysis is used to diagnose disease in tissue. For example, data from spectral scans performed on the tissue of a patient are used to screen tissue for disease. Some diagnostic procedures include the application of a chemical contrast agent to the tissue in order to enhance the image and/or spectral response of the tissue for diagnosis. In an acetowhitening procedure, acetic acid is used as the contrast agent. Use of a contrast agent enhances the difference between data obtained from normal tissue and data obtained from abnormal or diseased tissue.
Current techniques do not suggest an optimal time period following application of a contrast agent within which to obtain spectral and/or image data for the diagnosis of disease, nor do current techniques suggest how such an optimal time period could be determined.